Alert archive / Wisconsin / Flash Flood Warnings in 2021

Flash Flood Warning 8, NWS Green Bay, WI

August 28, 2021Brown County, Outagamie County, Wisconsin

NWS Green Bay, WI issued this flash flood warning at Aug 28, 2021, 12:34 AM CDT for Brown County, Outagamie County, Wisconsin. It was in force for 84 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 28, 2021, 12:34 AM CDT (05:34 UTC)
Expired: Aug 28, 2021, 1:58 AM CDT
In force: 84 min
Issued by: NWS Green Bay, WI
Area: Storm-based polygon
Flood severity: None

Counties Brown County, WI, Outagamie County, WI

The radar

The Green Bay radar (KGRB), 19 km from the middle of the area, began a volume at 05:38 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Aug 28, 12:35 AM CDT	FLOOD	Black Creek, WI	ALSO SOME MINOR FLOODING IN APPLETON.
Aug 28, 1:00 AM CDT	FLOOD	Green Bay, WI	MINOR FLOODING ON UNIVERSITY AVENUE.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 00:00Z, 5.6 hours before the alert went out and 20 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 552 J/kg
Mixed-layer CIN: -77 J/kg
Mixed-layer LCL: 916 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 179 m²/s²
0-3 km storm-relative helicity: 278 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 1.6

Open this sounding in Storm Lab

The text

As transmitted.

270 
WGUS53 KGRB 280534
FFWGRB
WIC009-087-280900-
/O.NEW.KGRB.FF.W.0008.210828T0534Z-210828T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Green Bay WI
1234 AM CDT Sat Aug 28 2021

The National Weather Service in Green Bay has issued a

* Flash Flood Warning for...
  Brown County in northeastern Wisconsin...
  Outagamie County in northeastern Wisconsin...

* Until 400 AM CDT.

* At 1234 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. The expected rainfall rate is 2 to 3 inches in 1 
  hour. Additional rainfall amounts of 1 to 3 inches are possible in 
  the warned area. These storms have a history of producing flash 
  flooding.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Green Bay, New London, Denmark, Black Creek, Bellevue Town, 
  Oneida, De Pere, Howard, Ashwaubenon, Bellevue, Allouez, 
  Ledgeview, Hobart, Seymour, Wrightstown, Hortonville, Humboldt, 
  Glenmore, Shiocton and Bear Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 4455 8873 4458 8776 4433 8777 4432 8874

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...2-3 INCHES IN 1 HOUR

$$

Kurimski

1 follow-up statement

505 
WGUS73 KGRB 280658
FFSGRB

Flash Flood Statement
National Weather Service Green Bay WI
158 AM CDT Sat Aug 28 2021

WIC009-087-280708-
/O.CAN.KGRB.FF.W.0008.000000T0000Z-210828T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Brown WI-Outagamie WI-
158 AM CDT Sat Aug 28 2021

...FLASH FLOOD WARNING IS CANCELLED FOR BROWN AND OUTAGAMIE 
COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 4455 8873 4458 8776 4433 8777 4432 8874

$$

Kurimski

The office that day

Everything else NWS Green Bay, WI issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 27, 7:25 PM CDT	Areal Flood Advisory	GRB	Outagamie, Portage, Shawano, Waupaca	2 hr
Aug 27, 7:52 PM CDT	Special Marine Warning	GRB		68 min
Aug 27, 7:55 PM CDT	Severe Thunderstorm Warning	GRB	Brown, Oconto, Outagamie, Shawano	65 min
Aug 27, 8:35 PM CDT	Special Weather Statement	GRB	Kewaunee	40 min
Aug 27, 9:08 PM CDT	Special Weather Statement	GRB	Calumet, Winnebago	52 min
Aug 27, 9:53 PM CDT	Areal Flood Advisory	GRB	Marathon, Portage, Waushara, Wood	3 hr
Aug 27, 9:59 PM CDT	Special Weather Statement	GRB	Calumet, Manitowoc	61 min
Aug 27, 10:36 PM CDT	Areal Flood Advisory	GRB	Calumet, Manitowoc	3 hr
Aug 27, 10:39 PM CDT	Areal Flood Advisory	GRB	Outagamie, Shawano, Waupaca, Winnebago	3 hr
Aug 27, 10:58 PM CDT	Flash Flood Warning	GRB	Portage, Wood	3 hr
Aug 27, 11:32 PM CDT	Special Weather Statement	GRB	Oconto, Waushara	58 min
Aug 27, 11:51 PM CDT	Flash Flood Warning	GRB	Waupaca	3 hr
Aug 28, 1:38 AM CDT	Areal Flood Advisory	GRB	Brown, Calumet, Manitowoc	82 min
Aug 28, 7:41 AM CDT	River Flood Warning	GRB	Wood	21 days
Aug 28, 10:14 AM CDT	Beach Hazards Statement	GRB	Door	33 hr
Aug 28, 10:14 AM CDT	Small Craft Advisory	GRB		33 hr
Aug 28, 10:36 AM CDT	River Flood Warning	GRB	Wood	48 hr
Aug 28, 5:17 PM CDT	Special Weather Statement	GRB	Manitowoc	58 min

Nearby

Flash Flood Warnings in Wisconsin, 2021 Every flash flood warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.